They used to commonly be surveys for 1,000 Robux if the player participates, events, and many more important messages, but currently, they are mainly just news and community activity.They are messages which are part of a user's Inbox. They are automatically sent to a user on Roblox, and cannot be archived, since they automatically delete themselves after a given period of time. News posts usually notify users about recent updates, which go anywhere from critical bug patches to advertisements about the latest gear. News posts are usually sent by admins, specifically Telamon or reesemcblox, but now it is only labeled as Roblox.
News were once called "notifications", which caused confusion to new users. The name was changed to "News" as a result of a recent update. There are usually one to two news posts sent out to a user.